#include <bits/stdc++.h>
using namespace std;
struct ListNode {
	int val;
	ListNode *next;
	ListNode() : val(0), next(nullptr) {}
	ListNode(int x) : val(x), next(nullptr) {}
	ListNode(int x, ListNode *next) : val(x), next(next) {}
};

class Solution {
public:
	ListNode* swapPairs(ListNode* head) {
		ListNode* dummyHead = new ListNode();
		dummyHead->next = head;
		ListNode* cur = dummyHead;
		while(cur->next != NULL && cur->next->next != NULL){
			ListNode* tmp = cur->next;
			ListNode* tmp1 = cur->next->next->next;
			
			cur->next = cur->next->next;
			cur->next->next = tmp;
			tmp->next = tmp1;
			cur = cur->next->next;
		}
		return dummyHead->next;
	}
};

int main(){
	
	return 0;
}
